This invention relates to a remote control tool monitor and assembly qualifier that verifies that the correct number of fasteners have been properly installed into an assembly. When used in conjunction with a mechanical click wrench, proper fastener torque and count can be verified.
Industry long has used compressed-air screw or bolt tighteners having a driving motor which drives a driving shaft for a screwing or tightening tool. The motor is operated by compressed air and a control valve for switching the compressed-air supply on or off. A pressure-regulating valve is used to regulate the screw or bolt tightener. Compressed air, fluids such as oil, electric current and mechanical pressure may drive the tool. Programmable controllers and computers also are known to be a part of the closed loop for monitoring and controlling the driving force of the tool.
U.S. patent application Ser. No. 08/936,187 (Lysaght), assigned to the instant assignee and herein incorporated by reference discloses an assembly qualifier that is a counting apparatus that monitors either the pressure of an air tool, the current of an electrical tool or the torque of a mechanical wrench to determine if the tool has shutoff at a target torque. The qualifier also determines if some unknown means shuts off the tool.
The remote control qualifier of this invention is an apparatus for monitoring a mechanical torque wrench with torque switch. The torque wrench includes a means for electrically stimulating the torque switch wherein the torque switch can provide an electrical signal upon reaching target torque. The torque wrench also includes a transmitter for sending the electrical signals to a receiver. A remote qualifier includes a receiver for receiving the electrical signals from the transmitter of the torque wrench. The remote qualifier also includes a means for electrically computationally processing the electrical signals into other signals representing at least one parameter corresponding to a condition of the tool being monitored which is a function of the condition, wherein the means for electrically processing the signals includes a programmed microprocessor configured to identify a portion of the signals representative of the switch condition corresponding to the parameter, and a means for displaying the parameter. Preferably, the qualifier is a radio frequency (RF) qualifier.
The RF qualifiers (tool transmitter and AQ receiver) operate in the 900 MHz range. Preferably, one of eight different frequencies can be selected so that multiple units can operate in close proximity. A rolling code algorithm is implemented in these devices to ensure that cross talk between units that are set to the same frequency is impossible. Before using a given tool with a qualifier, both units need to be set to the same frequency. The qualifier must also learn the xe2x80x9cseed codexe2x80x9d of the tool""s transmitter.
An RF qualifier used with mechanical xe2x80x9cclickxe2x80x9d (torque) wrenches will illustrate the apparatus. While many versions may exist, three other versions of the assembly qualifier are singled ported air tools, dual port air tools and electrical tools.